1. Field of Invention
The present invention relates generally to automotive powertrain systems and, more specifically, to a transfer case for an automotive powertrain system.
2. Description of the Related Art
Conventional automotive four-wheel-drive systems known in the art typically include an internal combustion engine that outputs rotational torque to a transmission which, in turn, adjusts the rotational speed and torque. The transmission subsequently translates rotational torque to a transfer case which, in turn, is configured to selectively translate rotational torque to a rear differential in rear-wheel-drive mode, or to both the rear differential and a front differential in four-wheel-drive mode. To that end, transfer cases typically include a housing supporting a series of shafts, gears, chains, clutches, and linkages which cooperate to effect selectable translation of rotational torque to the differentials. The transfer case is typically lubricated with oil and may include a pump assembly configured to transfer oil to the various shafts, gears, chains, clutches, and linkages in operation. Depending on the application, the transfer case may alternatively be designed without a pump assembly, whereby oil is transferred throughout the housing via windage forces generated by movement of the shafts, gears, and/or chains.
Each of the components of transfer cases of the type described above must cooperate to effectively selectively translate rotation from the transmission to the differentials. In addition, each of the components must be designed not only to facilitate improved performance and efficiency, but also so as to reduce the cost and complexity of manufacturing the transfer case. While transfer cases known in the related art have generally performed well for their intended use, there remains a need in the art for a transfer case that has superior operational characteristics, a reduced overall packaging size, reduced parasitic losses, increased efficiency and, at the same time, that reduces the cost and complexity of manufacturing the components of the transfer case.